It is known to provide various objects with a magnetized surface to enable them to be fixed temporarily on a ferromagnetic support such as a refrigerator door, an armored door, or the like. Plates of iron have also been used as supports for games containing magnetized pieces, such as chess games. Unfortunately, most surfaces such as walls, pieces of card, or the like, are not capable of retaining magnets. Similarly, flexible magnetic media suitable for being rolled or folded are not commonly available.